Spin-Meissner effect in systems of coupled polariton condensates

Abstract: We theoretically investigate the interplay between Zeeman splitting and TE-TM-induced spin-flip tunneling in coupled exciton-polariton condensates systems and its impact on the spin-Meissner effect. We demonstrate that although a single condensate exhibits the effect of full paramagnetic screening via spin-anisotropic interactions, the inter-site spin-flip tunneling can dramatically alter this behavior. The geometry of the system is shown to play a crucial role. In particular, in a dyad, the chemical potential reveals quadratic scaling with the magnetic field. In a triangle, the competition between Zeeman and TE-TM splittings produces a rich phase diagram that features asymmetric polarization states corresponding to both positive and negative magnetic susceptibility. In a square configuration, the symmetry of the network can restore the spin-Meissner effect, so that the condensate emission frequency becomes magnetic field independent in an extended parameter range. These findings not only shed light on the fundamental physics of polariton lattices but also suggest promising avenues for engineering robust spin-controlled photonic devices and polaritonic simulators.